1. Field of the Invention
The invention relates to a composite material having a substrate material and at least one barrier coating applied to one side of the substrate material, and to a process for producing a composite material comprising a substrate material and at least one barrier coating.
2. Description of Related Art
To reduce the permeation of gases and liquids in the field of plastic packaging and to protect the plastic material from chemical attack or UV radiation, it is advantageous for substrate materials, in particular plastic substrates, to be provided with a barrier coating. Barrier coatings allow the same property to be achieved with inexpensive bulk plastics as with expensive specialty plastics and make it possible to replace glass, for example, in the field of pharmaceutical packaging materials with bulk plastics of this type. Applications of barrier coatings to a plastic substrate have been disclosed by the following applications:
U.S. Pat. No. 5,798,139
U.S. Pat. No. 5,833,752
U.S. Pat. No. 6,001,429
U.S. Pat. No. 5,798,139 describes the production of plastic containers with a carbon film coating. The carbon film is intended to form a gas barrier and to solve the problem of sorption from the plastic material.
U.S. Pat. No. 5,833,752 has disclosed a system in which the barrier coating is applied from a plasma. The energy used to maintain the plasma is applied by devices which are distinguished by the fact that the energy is introduced into the interior of the containers to be coated via an outer electrode.
U.S. Pat. No. 6,001,429 again discloses the application of a barrier layer to the inner surface of a plastic substrate, with HMDSO as monomer gas together with an oxygen carrier gas being passed into the interior of the item which is to be coated.
It is an object of the invention, working on the basis of U.S. Pat. No. 5,833,752 and/or U.S. Pat. No. 6,001,429, to provide a composite material and a process for producing a composite material of this type which is distinguished by an improved barrier action and improved bonding to the plastic material.